If Canon manages to differentiate a 6D and a 7DII enough I can image both existing at the same price point: 6D for landscapers and wide angles, 7DII for action and "reach". Built, AF, frame rate have to top the 70D. Maybe it has an integrated grip. The question is if there are enough people who are interested in a mini 1Dx. I think so. The next question is if Canon sees this. Again I think so.

I don't, really. The number of new sales (this is people who would buy that and not buy a 70D or 6D) would have to be enough to pay for the R&D costs of a completely new model, which would not be low. Consider, Canon has an APS-C mech which supports 8FPS, presumably they use this mech in the 70D. To go faster it is likely they will need a completely new mech, since the mechanical forces rise exponentially as FPS rises. Then they don't have an APS-C AF system better than the 19 point one, so they would need to develop that (the 1D X system is too large for the APS-C frame) - all in all a completely new camera for low sales. Can't see it being economic. Could be wrong, but I don't think that I am.

Then consider this, the 70D introduces the 20MP sensor. The 18MP sensor was introduced in the 7D, which appeared some time before the 60D. Why is not the 7D Mk II being introduced first? The best way to phase this introduction, if they are doing two, is to release the high end model first as they did the last time, then it has added sales from the new model halo effect and has the market to itself. The risk of doing it the other way is that unless the spec is very high, unfavourable comparisons will be made about the VFM of the new one.

The 7D was released first because it had the new sensor which would later be included in the 60D but the new model needed to be established first. That isn't the case this time. Everyone knows that Canon now has a high-end APS-C line and they'll be willing to wait for its update.

I doubt that 'everyone knows' that. I think a good few people will decide that the 70D is good enough for them and go for it. Similarly, quite a few who might have spend their money on a 7D MkII will have been tempted by a 6D. The question is, whether those sicking out for a 7D Mk II and nothing else are numerous enough to pay what will be a big R&D bill.

Yes, people shopping for a DSLR who have looked into Canon APS-C bodies ALL know. The 7D has become legendary. I'd suspect that's why people are so butt hurt that Nikon hit the market with their next gen before Canon did: Canon has been leading so long now people are more impatient than they have any right to be. The 6D is a great low-end full frame and the 7D is a great high-end APS-C, so many will be tempted who want full frame but can't afford the high end features. That's probably not a huge number.

Also, if the 7DII also differentiates itself by having a 24 or higher MP sensor it will truly be in a class of its own.

Especially if it has a new sensor which won't be used for anything else. This isn't what Canon has ever done before. What they have done before is release the new sensor in the top APS-C model (xxD or more lately 7D) and then trickle it down to lower models. So, 8MP sensor was first in 20D then 350D. 10MP sensor first in the 40D then in 400D and 1000D. 15MP sensor first in 50D then in 500D. 18MP sensor first in 7D, then 60D then 600D. Only exception is the 12MP sensor which only ever appeared in Rebels.

The 7D was never done before it was done. The 6D is a brand new full frame sensor just used in the 6D. The G1 X sensor is a brand new sensor just used in the G1 X. Sorry, but Canon has been doing some interesting market diversification over the last four years and especially the last year or so with those bodies, the SL1, and the M.

Canon knows they need to get the 70D out and if the R&D for the 7DII is behind schedule then they'll do what they have to do despite it being less than optimal. They've done it before and they'll do it again. They may have gotten a bunch of upgraders with the 7D, but they also had to wait longer for the 60D to get the Rebel upgraders and the XXD upgraders that weren't up for spending a few hundred extra for a 7D. I'd bet there were equally compelling argument for either release schedule and the net difference between the two was about zero.

I don't think that is what happened at all. I think that the 7D was the 60D, then Canon re-used the 60D name to start a new line of camera somewhat below the old xxD line. Now I think they are re-unifying. xD means FF from now on.

No, the 7D had much higher end features, some of which had never been put in any cameras, on board. The 60D we expect was not to be, instead it was a lower end XXD AND a high end body in the form of the 7D. You think XD is now FF and the 7D will be abandoned? I'd put a hundred bucks on that and even give you odds.

Canon knows how to make very high frame rate shutters with very highly rated lifespans.

Well no, they buy them in from specialist shutter manufacturers, like everyone else.

And yet Canon always leads the pack. Wherever they get them, they get the good ones.

They put the new stuff into the high end bodies and as costs come done it hits lower and lower on the food chain.

No, they don't - not with shutters and mirror boxes. Canon very rarely designs those new, and they very rarely feed it down the food chain. It would make the product unreasonably expensive to put a shutter specified better than needed.

Very rarely? I guess that's why the 7D was invented. They finally started putting 100k rated shutters in APS-C bodies. It isn't better than needed and they charged for the privilege. I didn't say they were giving things away for free. Oh, and don't forget the 1D X. Rare or not, they know how to do it.

I don't think there is any reason to doubt Canon's ability to strategize as appropriate to the technology they have developed or are currently developing.

Indeed, an my bet is that they are 'strategising' to stay with a four model APS-C range, but differently configured. They have already moved a new model in with the 100D. With FF moving down in price that space gets crowded, I can't see them moving to a five model range, makes it even more crowded. I think they are doing what they have always done, introducing new sensors at the top of the DX line and will move them down, putting them in the existing mechs to refresh all the APS-C models over the next two years.

Moving down and now their low end FF segment is filled well above the price of the 7D was originally....and the 6D is lower spec'd in many key regions. I'd bet on a 7DII with the high end features and a new sensor for the same sticker as the last was. Crowded is only crowded if they aren't flying off the shelves, my friend. The SL1 and M compete in the ILC market, the Rebel stays put, the 70D keeps its standing, and the 7D fills in the gap between a $1,200 C and the $2,100 FF....how is that crowded? It's in the same spot in the C line and will out spec the 6D in all but FF sensor. There is no other gap in their lines that is $900 wide and why would that change? The 70D, if these specs are right, is going to be a 7D in most respects with a slightly higher res sensor and lesser build quality. The 7DII is primed to kill in the high end APS-C field.